One prior art patent disclosing a catalytic combustor such as may be used in the production of steam for enhanced oil recovery is U.S. Pat. No. 4,237,973. Another combustor which may be used to produce steam downhole includes U.S. Pat. No. 3,456,721. One method of start-up for a downhole combustor is disclosed in U.S. Pat. No. 4,053,015 relating to the use of a start fuel plug. Some characteristics of fuels used in combustors are mentioned in U.S. Pat. No. 3,420,300 and the injection of water to cool products of combustion are disclosed in U.S. Pat. No. 3,980,137. Another United States patent which may be of interest is 3,223,166.